1. Field of the Invention
The invention relates to a method and a system for determining the dependence between device parameters of a mobile telephone and signal parameters of a signal transmitted and/or received by the mobile telephone.
2. Related Technology
One important stage in the manufacture of mobile telephones, which is implemented in order to identify faulty mobile telephones at the end of the manufacturing process, is testing the quality of different signal parameters, for example, the error-modulation vector (EMV) or the code-domain parameters (CDP) of the signal transmitted or received by the mobile telephone under test dependent upon given device-parameter values in the reception and/or transmission channel of the mobile telephone, such as the offset voltage of the reception or transmission amplifier. For this purpose, the measured signal parameters are compared with threshold values, which define the correct tolerance range.
In the case of purely static-process tests, in which the continuously-measured values of the individual signal parameters of the signals transmitted and/or received by mobile telephones are merely archived for evaluation at a subsequent time, a comparison of threshold values and the consequent separation of faulty mobile telephones are not required.
For both fields of application, identification of faulty mobile telephones and static-process measurement of process parameters, a short testing time is desirable in addition to high-precision testing. Particularly in the context of tests, in which the mobile telephone must be measured with regard to several signal parameters of the transmitted and received signal over a plurality of transmission and reception frequencies and respectively over a plurality of device-parameter values of several device parameters, the testing time can have a negative influence.
The frequency and signal level of the signal received by the mobile telephone are conventionally transmitted from a superordinate procedural-control unit to the measuring instrument, and the frequency and signal level of the signal transmitted by the mobile telephone are transmitted to the mobile telephone together with the device-parameter values of a device parameter to be set in the mobile telephone, and, after triggering with subsequent synchronization of the measuring instrument with the mobile telephone, the measurements of the individual, relevant signal parameters of the transmitted and/or received signal of the mobile telephone are then registered by the measuring instrument.
Transmission times for the transmission of the individual frequencies and signal level of the transmitted and/or received signal to be tested and for the individual device-parameter values in some cases of several device parameters of the mobile telephone are also disadvantageously added to the actual testing time. This significantly increases the total time for measuring all signal parameters of the signal transmitted and/or received in all frequencies.